Piston and ring



y 1932- E. s. REILAND ET AL 1,868,075

PISTON AND RING Filed 0ct 29, 1926 Zl Ernest S? Rez'land Peter M ReilandPatented July 19, 1932 i Y i 1,868,075

" ATE' NT Z QF f Emvns'r SQREILAND AND PET R M. BEILAND, or ST. PAUL, MINN IfISOTA irIs'ron Ann mm Application filed dctober 29, 192 serial No.4mg i 7 Our invention relates to piston and rings wherein it is desiredto providemeans for centering the piston in the cylinder so jthat as-thepiston reciprocatesb ack and forth in the engine, it is held positivelycentered and at the same tlme 1S preventedfrom piston clearanceslapwhich is "partlcularly true in aluminum and alloyed pistons where sumcient' clearance is necessary to allow for expansion. V j A feature ofour 1nvent1on resides part cularlyin' a piston which can be" made ofaluminum or alloy metal having 'a' "light .Weight and of such aConstruction as to be permitted to be fitted ivery loosely in thecylinder; This will allow for the expansion of the metal without thebinding of the piston' Ordragging of the same on the cylinder i wall, infact, our piston is so constructed and 7 so held by our bearingringsthat it is possible to make the diameter of the piston so smallthat it would be impossible for it to expand sufficiently under ordinaryconditions Our invention includes a partlcular construction and having aparticular function in operation which is adaptedto hold the pistoncentered in the cylin der during its reciprocation.

Our piston ring functions automatically to center the piston andprovides the necessary bearing for the piston in the cyllnder so thatthe piston may run't'rue without clearance; I slap and practicallysilent within the 'cylina der on either stroke of the connecting rod,

Cur piston-ring is designed to provide a double hearing which extendsannularly and Which engages with complemental bearing surit'aces formedon the piston. The bearing of thepist'on ring on the complementalsurfaces formed in the piston, which 'are approximately in parallelrelation, such that during the explosion in the cylinderfthe directedpressure of the explosion is against the upper, broad, edge so that thepressure oftheexplosion in the cylinder will assist in forcing thebearing surfaces of the ring, which extend on a bevel, into con} tactwith the complemental bearing surfaces in tlie'piston so as to provide atight joint a bearing ring of betweenithe piston and piston ring andjiatthe same time to automatically cause the pistouring to bear firmlyagainst the cylinder w wall to provide the desired compression; inthe'lcylinderl The operation of the piston andring is automatically infthecentering of the pistonbody in the cylinder and the, positioning oft'he piston rings in operative position. e p e I "In our'piston therings have a double functionin vfornriing the compression ring's for thecylinder at thehead ofthesame and also in providing centering and:guidingf means for the piston at the head and atthe'skirt it usedheretofore insofar as we know and 'we'f believe that, this an importantfeature of our inventionas' 1t permlts us to secure a higher compressionby the tests which we have made andv yet reduce the "frictional surfaceordinarily contacting with cyli incler wall'so' that our" pistons seemto run very freely in the cylinders when in ope'ra tion. i

Our invention includes resilient 1 means adapted to be positioned withinthe ringsand thereby practically concealed back of;the same. Thisresilient means "is adapted to function to hold the piston rings underspring tension in contact with thebearing surfaces on the piston therebyproviding adouble comparatively oil tight joint between the piston andring and between thecylinderwaill and the piston and ring This resilientmeans operates automatically to hold the pis ton ring against slappingin relation to the piston 'an'd' is concealed and protectedfby the Iring. The invention includes a formation of the piston so as to causethe resilient means i for engagingthe ring to have a tendency tocontract inwardly, the formation in the piston beingof anarcuated natureand the p1ston ring is provided with a shoulder against which theresilient means engages so as to hold the piston ring under spring,tGIISIOII withthejpis'tonandcylinder wall at all times.

the cylinder, the ends of the ring over-lap The piston ring of itselfhas an expanding 7 nature as the piston rings are ordinarily contractedintoiposition on, the piston and .as the rings are contracted theresilient means back of the piston ring is adapted to be slightlyexpanded, thus providing the necessary tension'for holding the pistonring under ten-1 'sionion the bearing surfaces on thepiston andpreventing any slapping or clicking of thegpiston'rings in the operationofthe piss It is also a feature Of 0111i invention toproin'ainannertoform' a practically oil and coin s pression tight "joint; 5This is a very important feature; of our invention for it may bewell'considered that here'tofore'noil,leak t-ogether'with compressionleakfhas been. ex-

" perienced at the; joint ofthe ordinary 1 piston rings}The'construotion of'our piston ring with the" piston :is such that widebear mg; surfaces arelprovided and a doubleoffset jointi's permitted sothat a practically oil and. compressionv tight joint is, accomplished;Our .inventiontalso includes "oil control me'ansin the formation. of thebearing ring and openings formedfin the pistonwhich are particularlyadapted to; the ring just above the wrist pinblearing ofz the piston.VBy: a

.tion and claims. 7 p v V j n In the" drawing forming part of this specisharp edge formed on the lower. portion'of one. of the rings, the oil isheld down-in the cylinder and adjacent 'thisedge a series of openingsextend through the piston permitting the 'oil to drain back to thecrankcase.

{These objects and. details: together with. other features of ourinvention'willjbe more fully and'clea-rly set forth in the specificavfication r Figurellfillustrates a portion ofa': cylinderav n :s p andings thereimypart which: vis n away and illustrated in cross'sectiori, a

- c Figure 2 is. an' enlargedcross section one our rings.

of; ouripiston rings.

Figure?) ji'san enlar'ged detail of a portion of ourpistonring.

'.,Fig.ure flis- -aperspective of the double off-V setjoint of ourpiston ring. v r j :Figure 5 illustrates neof the springs or resilient:members used in conjunction; with In the drawing we have illustrated ourpiston A with the head portion 10 which in this particular constructionprojects up slightly above the rings, however, this is not essential ornecessary in the construction of our pistonythis form of head ofthe'piston is used by a well known make of automobile engines. 11" Pi onA is designed toib ma f aluminum or an alloy of metals to provide. 7 V apiston with a very light weight but hav "ing a: substantial-unseVer-edbodyiportion 11 V which canbe loosely fitted within the cyl-1 inder B.'Only a portion of the cylinder B isillustratedin the drawing.Therefore, the expansion of" the piston A will beconsiderably less thanthe diameter in the cylinder B so that the piston A cannot bind orv dragin r the cylinder. n a V Our piston 'A is provided'with the skirt 12which depends from the head portion 10' below the wrist pin bearing 13.It is therefore apparent thatltherings for our piston become thecompression rings at theto p or head "and also. form guide and bearingrings ,to centerthebody of the piston withinxthe cylinder, thusequallyspacing the same away from the wall of the cylinder and permitting theuse of ai'piston with a large clearance,

having no piston clearance slap. 1. Y

It is to -be;considered that the split skirt piston is objectionablealso because it requ res a re-enforcmgofsome substantial material togive a proper support for the wristpin bearing as it is apparent thatthe force the connecting rod to the crankshaft. In

our piston we overcome the necessity of split-1.

ting the skirt to prevent the piston from eXpandin too tightly :againstthe cylinder Wall and .wealsoovercome the piston'clear ance slap byprovid ng means for hold'lngf the piston centered in the cylinder.

This

permits us to use a piston body of a much I smaller size S than couldordinarily be usedq .Then byv reason of the fact that we do not 7 splitthe piston, we obtain aflvery substantial and rigid support for thewrist pin bearing of the connecting rod together with a simpleinexpensive construction;

Our piston rings C are designed with a I wide face-hav ng a doublebearlng surface 14 extending about the same whilethe center portion 15is cut away to form a recess,

leaving the bearing surfaces 14; on either side of thefringCQ Thisconstruction provides a ring withthe equivalenceof a wide bearing face,yet'reducingthefrictional-contact 7 bearing surfaces of the ring about.the outer 7.

by the recess portion*15 and pressing the edgeso that-the ringmay'function in a manner togive the advantages of a wide contact, yet havlng a much lessiactual "frictional bearing than if the entire width ofthe ring C engaged the cylinder wall 16;

of the "explosion in the cylinderfcoming against the piston'istransmitted through.

. practically of a triangular shape which are The ring C is formed withinwardly projecting portions 17 and 18 which have shoulder portions.19and 20 respectively project-2i ing approximately at right angles to theface '14 andbeveled surfaces 21 and 22 respectively which extendapproximately parallel to each other to provide beveled bearing surfacesfor the back of the ring C. This construction provides the ring C withacross section wherein the portions 17 and 18 "are joined togetherintegrally by the center portion 23 of a narrow thin wall nature incross section as illustrated in Figure 2. By this construction of thering C in addition to the spaced apart bearingsurfaces 14 whichpro' videthe equivalent of a. wide bearing for cesses 24 to provide portions onthe outer surfaces of the piston which may be machined to form thebeveled surfaces 25 and 26, adapted to form the bearing surfaces for 1the beveled surfaces 21 and 22 of the piston ring C so that the pistonring C when posi tioned on the piston A will be adapted to bear with thesurfaces 21 and 22 against the complemental surfaces 25 and 26respectively.

' \Ve provide a ring O which havinga wide.

nature, in cross section,' permits the formation of adouble offset jointso asjto provide a piston ring C with practically an oil and icompressiontight joint' This permits us to out the ring C to provide thedouble offset joint 28 with overlapping end portions 29 and 30. The endportions 29 and 30 are of practically the same general construction 1and are so formed as to provide a l0ngitudi-.

nal cut portion which permits the lapping of the ends 29 and 30 to comeat apoint within the surfaces 21' and 22 so that'when the rings'C areheld in position on the cylinder A, the overlapping, ends 29 and 30 willbear against the beveled surfaces 25:and 26respec-1 tively in a mannerto close the joints or overlapping ends of the ring and thereby providea piston ring which may be used as a compression ring, a bearing ringand a 'pract-i-'- callyoil tight ring. It would be'readily apparent thatthe bearing of the surfaces 21 and 22 against the beveled surfaces 25and r 26 will approximately prevent oil from creep- 60: ingback of thering and this is a very important feature of our invention. 7

To facilitate the proper operation of our We provide a coil spring Ewhich is adapted to be positioned-between the portions17- and 1.8 withthe spring E bearing against theinner shoulder 20 ofthe rings (landbeing, practically concealed within the recess 24 by the'ring C. v Therecesses 24 in the piston A; are formed with an arcuated surface 32 toprovide a bearing surface and recess for ,the c011 spr ng E on thepiston A and toicause the spring E to have a tendency to operate morereadily with the piston rings G'to cause them to be pressed firmlyagainst the bearingv surfaces 25fand 26 on the piston, in fact, the

coil springs E will be inclined to draw to-' gether and move into thedepth of the recess 24 while the engagement of the shoulder 20. of theringC with the spring E willhaveia tendency to expand the springs andforcethe same-slightly out of the depth of the recess 1 24;, thus as therings C are=1i ositionedwithin; the cylinder 13, they are, compressedsufli-' eiently to properly contact with "thewall 16 and asufiicienttension is brought to bear" against the spring E'which extendsannularly in the groove 24; to'hol'dthe rings con-z stantly under springtension .against the beveled'bearing surfaces 25 and 26 formed in thepiston. A.

l Ve have illustrated two our ringsflp'o sitloned in the head of thepiston A which are adapted to form bearing and compression I.

ringsoperating in a manner'to center the head of the piston in thecylinder B being held by the spring means E. "These rings.

are practically silent; in the operation. or

reciprocation of the piston and at the same time are held 1n a manner soas to press:

against the surfaces 25' and 26 with the sur-, V faces 21 and 22respectively toform a'double.

oil and compression tight joint in back of the ring while the outerbearing surfaces 1 1 form a' tight joint with the 'wa'll 16of thecylinder. It will therefore be apparent that .7

a very important function is performed by our rings C in overcomingprimary diiliculties which have been apparent inthe opera tion ofpistons heretofore, The springs E 'are protected andpracticallyconcealed by the rings C and-may be of any suitable coni struction ornature to function to hold jt-he rings Clbearmg under-spring tensionagainst the. surfaces 25and'26. As the surfaces 21 and 22- are ofpractically the same bevel: and

lie in practically the same plane as the sur faces-'25and 26, it willreadily be apparent that the ring G'will formjthe desired means piston Ato be cento cause the 'body of the tered within the cylinder.

The upper ring (Jon the piston A adapt.- ed to receive a portionof theforce of the. explosion: and compression'o'n the shoulder 1 1:9assisting the spring means E in forcing r the rin ti htl a ainst thesurfaces 25 and D h piston rings, which are adapted to form bearin comression and oil control I1I1(T 26 in anianner to provide meansfor'cent'eroperating automatically in the reciprocation ofthe same.

of the two rings placed in the head of the piston A, is, provided with asharp annular view in Figure 2, so as to provide 'ameansj of collectingthe oiloff-of the wall 16' and we- 'provide an annular groove'35'inthepiston of openings 36 extending:through the wall of the piston so asto permit the surplus oil to be drained through the openings 36 backinto the crank case. This construction per-' mits us to form our pistonA with-the proper lubrication'extending up to the rings C, yetpreventing a surplus of oil "from buil'dingup below the rings'but permiting it to drain back through the-piston to the crank case. Theskirt' 12of our. piston A is provided witli'a-similar groove or recess 2a whichis inverted in relation to the position of the grooves 24 at the toplofthe pistonancl with-in this "groove we provide a bearing ring G lowingclaims identical to the other bearingand compression rings" but-adaptedto act as a bearing for thelower or skirtendof the piston, and which is"adapted, to be held' in position against the beveled surfaces and '26by the spring means E inthe same manner as the other rings are held atthe top of the piston.

- In accordance with the patent statutes, we

have described the principles of operation of our piston and rin'g'andwhile we have illustrated a particular formation and construc-' tionofthe same in the drawing, we desire to have it understood that the sameis only illustrative asa' means ofcarrying out our inventionand thatth'esame may be applied and carried out by other means and to other" useswithoutdepartingfrom'the spirit of our invention and within the scope ofthe fol- We claim 1; A' piston including, a bod y-port-ion hav ing'beveled-surfaces extendin'g parallelly, a

piston ring adapted to engage said surfaces with complemental bearingsurfaces extending at approxlmately the same bevel asthe said beveledsurfaces on said piston-and f spring means between said ring and saidpiston for holding's'aidupiston ring under spring tension, in contactwith said bearing 1 in annular grooves extending about said-body 7portion, bearing ring members adapted to *fit said grooves and resilientcoiledmeans with surfaces formed in said piston. 7'

2. A self-centeredpiston including, bear ing and compressionringspositioned at the:

head and skirt, of said piston", resilient means for holding said ringsin contact "with. said piston and a pair of parallel complementalbeveled surfaces formed on said pistonv and ringstocause an annular sealto beformed aboutsaid piston between; the piston and rings and betweenthe rings and acylinderf. walL I I 3. A piston ring incl'udin'gspringmeans, spaced apart annular bearing surfaces on the "outer face thereof,aright angular-shoulder l s extending-from one" side of {said ring andannular beveled bearing surfaces formed on I, the inner surfaceofsaid'ring and spaced apartwitli aright angular slioulder'between isaidibearing surfaces adapted to form "en gaging means for said springmeans within the ring to hold the ring'in operative-pos'ition underspring tension on a pistonyj T4;'."A piston and bearing packing meansincluding, a piston ring having. a pair of parallel spaced apart beveledbearing -sur--- faces, compleinental beveledbear'ing surfaces formed insaid 'piston wall and spring means" concealed by said ring andadaptedito engage the same between said bearing surfaces? ina mannertohold said ring bearing against on 'sai'd'piston the beveled surfacesforme under 1 spring 1361151011;

5'. A piston including, means for centering the samein a'cylinderautomatically in the reciprocation of the piston, including bear-k ingsurfaces formed-onsaid piston, a ring resilient coiled spring n'ieansinterposed be tween said p ston and ring and positioned said bearingsurfaces.

6. A piston and ring including, a bearing surface formed on said-pistonhavingspaced apart beveled faces, a ring'adapted to engage said faces toform a compression andfoil' tight joint between said piston and ring andadapted to engage saidbearingsurfaces and resilient means engaging saidring-between said faces for holding said ring in contactwith said faces.

7. A piston and bearingfincluding, ring;

members adapted to be interposed betweenthe piston and cylinderwall,coinplenientalf V beveled bearing surfacesfor med on said ring and"piston, v resilient means interposed be tween the beveled surfacesofsaid ring and piston to hold said ring in contact with said beveledsurfaces, a sharp" ed ge' formed 011+ one ofs'aid rings adaptedto'colle'ct oil from the? "cylinder awall and openings formed throughsaid piston adjacent said'sharp edge:

to ldrain the surpl us oil back'throughesaid piston.

' A piston andbearing including, a cylin V drical body portion,bearingsurfaces formed its *fiXlS transversely disposed to-the pistonraxisback of said ring members-to hold said bearing surfaces in operat vepositioniunderj spring tension. r a 9. Apiston and bearing including,aseries of bearing, rings positioned in thehead of ton and rings,resilient means between said bevelled bearing surfaces for holding saidrings in operative position under spring tension, and an invertedbearing ring positioned in the skirt of said piston having complementalbearing surfaces with the piston and v resilient means between thebearing surfaces for holding said ring in operative position.

10. A piston including bearing and compression rings, each of which areformed with a cross sectional shape adapted to simulate a pair of equalright angular triangles, an integral Web portion formed in said rings,complemental bearing surfaces formed in said piston to receive thehypotenuse sides of said rings and resilient means for holding tensionagainst said complemental bearing.

said rings in operative position under spring surfaces.

11. A piston including, beveled bearing surfaces extending in pairs inapproximately parallel planes, a recess portion interposed etWeensaidpairs of bearing surfaces one side of said recess portion having anarcuated formation.

ERNEST S. REILAND. PETER M. REILAND.

